Compress image
Make an image smaller by lowering its quality, as JPEG, WebP or PNG. Everything happens in your browser and nothing is uploaded.
Add an image, choose a quality level and output format, and download a smaller version. The result card shows the before and after sizes so you can judge the trade-off rather than guess at it.
How the compression works
The picture is read into your browser's memory and decoded. Its type is identified from the file's own bytes, HEIC photos from iPhones are converted with a WebAssembly decoder, and the rotation stored by the camera is applied to the pixels. The picture is then drawn onto a canvas of exactly the same width and height and saved again with your browser's own encoder: JPEG by default, or WebP or PNG, at the quality set by the slider, 75 by default. Only the quality changes. The pixel dimensions stay the same, so the file gets lighter without the picture getting smaller on screen. Where the original had transparency, a JPEG gets a white background. The result is named with -compressed added, and the card shows its size before and after.
Limits
One image at a time, up to 100 MB; JPG, PNG, WebP and HEIC are accepted. The picture is always re-encoded, even at quality 100, and the result is not compared with the original, so an already well-compressed photo can come out larger. PNG is lossless here, so the slider does nothing for it, and choosing PNG rarely makes a file smaller. Camera data such as EXIF, location and the colour profile is not carried into the result. Where a browser cannot save WebP, the page says so and asks you to choose JPEG or PNG. Very large photos can fail where the browser limits the size of a canvas, which is more likely on a phone. To change the pixel size instead of the quality, use Resize image.
How to use it
- Add the image you want to shrink.
- Set the quality, and pick JPEG or WebP for the biggest savings.
- Press Compress image and check the size before downloading.
Why use this tool
Completely private
Everything runs inside your browser. Your files and text are never sent to a server.
Free, with no limits
No sign-up, no watermarks and no cap on how many times you can use it.
Instant results
There is no upload or queue to wait for, so results appear as fast as your device can work.
Works on any device
Runs in any modern browser on phone, tablet or desktop. Nothing to install.
Frequently asked questions
- How do I reduce an image's size in KB without changing its dimensions?
- Lower the quality slider. It changes how much detail is kept, not how many pixels there are, so the picture keeps its width and height while the file shrinks. For a smaller picture, not just a lighter file, use Resize image.
- Why did my compressed image come out bigger?
- The image is always re-encoded and the result is not checked against the original. A file that was already compressed hard, or a PNG, can end up larger. Try a lower quality, or JPEG or WebP instead of PNG, and compare the sizes on the result card.
- Does it compress photos from an iPhone (HEIC)?
- Yes. HEIC and HEIF photos are opened with a decoder built for the browser and saved as JPEG, WebP or PNG, whichever you choose. Only the first image in the file is used, and the result carries no camera data.
- What quality should I use?
- Around 75% is the usual sweet spot for photographs — a large size reduction with no visible difference at normal viewing size. Go higher for images that will be printed or zoomed into, and lower for thumbnails.
- Which format compresses best?
- WebP is typically 25-35% smaller than JPEG at the same visual quality, and every current browser can open it, although not every browser can save it: where yours cannot, the page asks you to choose JPEG or PNG. Choose JPEG when the file has to work with older software or be accepted by a form that does not recognise WebP.
- Why does PNG not get smaller?
- PNG is lossless, so the quality slider does nothing for it — that is why it is disabled. To shrink a PNG photograph meaningfully, convert it to JPEG or WebP. PNG is the right choice only for screenshots, logos and images with sharp edges or transparency.
- Are my images uploaded anywhere?
- No. Compression uses your browser's own image encoder, so nothing is transmitted. That also means speed depends on your device rather than on someone else's queue.
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